Police say a woman robbed a Sioux Falls bank by claiming she had a bomb. Police spokesman Sam Clemens says the woman didn't show any weapon during the holdup Tuesday. She fled with an undisclosed amount of cash. No injuries were reported. Clemens says there weren't any customers in the bank during the robbery. Sioux Falls Police Sgt. Kyle Hoekstra tells the Sioux Falls Argus Leader the incident is unusual because the robber was female and she mentioned a bomb. Hoekstra says most armed robbers have a gun or claim they have one.